Officers swooped on the man after he used a digger to retrieve the hidden cash from a field in Portcrusha, Castleconnell, Co Limerick.

The cash - €1.25m - was buried more than six feet underground and he was arrested in a nearby cabin as he counted the cash.

There was equipment for cleaning and packing the cash in the cabin and when officers swooped on Saturday the man was attempting to count and dry the stash.

He was last night being questioned by officers at Henry Street garda station in Limerick city. Another man was also arrested near the field. The two arrests came after a major surveillance operation was launched on the drug dealer several weeks ago.

The €1.25m had been buried so far under ground that the man had to use a mechanically operated digger to retrieve it.

It is not known how long the cash had been there and gardai are examining serial numbers in a bid to establish when the loot was buried.

"Only he would have known where it was buried. It was very carefully concealed. You would have to know where it was. That was the most valuable field in the country for a long time," an informed source said.

The cash was wrapped in plastic bags and some of it is believed to have been vacuum packed.

It was very wet when it was recovered and the criminal was attempting to dry, clean, count and repackage the cash in the cabin when gardai moved in on him.

The €1.25m is believed to have been made up of various denominations. It took investigating gardai two days to count the notes.

The area where it had been buried is located close to the Shannon River and the Limerick/Clare county boundary.

The criminal was previously sentenced to six years in prison after he was caught with 14 kilos of cannabis in Limerick city in 2000.

He is originally from the northside of the city but had been keeping a low profile since he was released from prison several years ago.

The two men were arrested under money laundering and terrorism legislation.

One of the men was later released without charge but the other was still being questioned last night.